A surcharge on every firearm, every round, and every “precursor part” — stacked on top of the federal excise tax and your regular sales tax.
Officially it’s the Colorado firearms and ammunition excise tax — created by HB24-1349, approved by voters as Proposition KK in November 2024, and effective April 1, 2025. It’s 6.5% on firearms, ammunition, and “firearm precursor parts,” legally imposed on the vendor’s net taxable sales — which dealers pass through in the price. It doesn’t stand alone: it stacks on top of the federal 10–11% manufacturer’s excise tax, plus your regular state and local sales tax.
Exemptions are narrow. Only peace officers, law enforcement agencies, and active-duty members of the U.S. Armed Forces are spared. Everyone else — every peaceable citizen exercising an enumerated right — pays the surcharge.
Know who the law puts on the hook: you, the vendor. You file monthly returns through Revenue Online by the 20th of the following month. And per the state’s own FAQ, an out-of-state vendor shipping into Colorado owes it too — so mail-order doesn’t dodge it. Build it into your pricing and your bookkeeping from day one.
They can’t ban the right outright —
so they price it like a vice instead.
Acquiring arms is part of keeping them — a right to keep what you cannot obtain is a dead letter, and courts have recognized that acquisition is covered conduct. Proposition KK’s 6.5% excise attaches a state-imposed cost to that protected act — not incidentally, but by design. The tax falls on firearms and ammunition specifically, because of what they are, with the revenue framed as remediation for the right’s exercise.
That is the textbook structure the Supreme Court has condemned when other rights were at stake — a state charging citizens for doing what the Constitution says they may freely do:
Murdock v. Pennsylvania — a license tax on preachers. Minneapolis Star v. Minnesota — a targeted tax on newspapers. Harper v. Virginia — the poll tax. Each was modest in dollars; each was struck down anyway — because the constitutional injury isn’t the amount, it’s the principle of the toll: a state charging citizens to exercise a right, with the implicit power to raise the price whenever it likes.
Once you concede 6.5% is permissible, nothing in the logic stops 15% or 50%. The power to tax a right is the power to price it out of existence — which is why the founding-era meaning of infringe — to hinder — matters: the tax hinders today and holds the machinery to destroy tomorrow. And under Bruen’s historical test, the plaintiffs’ point is that no founding-era tradition exists of excise taxes levied on arms to burden their acquisition — the analogues the state offers all come later, or fall on general commerce.
A tax that singles out an enumerated constitutional right for special treatment isn’t just expensive — it may be unconstitutional. In Langston v. Humphreys (Case No. 2025CV31185, Denver County District Court, filed March 31, 2025), a coalition is making exactly that argument, invoking the Supreme Court’s Murdock line — the cases that struck down taxes on First Amendment activity. The plaintiffs: the Second Amendment Foundation, the NRA, Firearms Policy Coalition, the Colorado State Shooting Association, Magnum Shooting Center of Colorado Springs, and citizen Zachary Langston.
The coalition is carrying this to court, but the movement is carried by members. The Colorado State Shooting Association is in the fight on the tax, the bans, and what comes next. Stand with them.
The author of this site is not an attorney and does not practice law. Nothing published here is legal advice, no part of it is offered as legal advice, and reading it creates no attorney-client relationship with anyone. This is Second Amendment advocacy and general-interest commentary written by a private citizen, and it includes opinion.
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